1. Field of Invention
The present invention relates generally to resource allocation for a virtual server, and more particularly, to monitoring and dynamically modifying the resource allocation for a virtual server based upon usage.
2. Background of the Invention
Networked computer resources are growing more popular as the benefits of sharing computing resources become evident. One of the fastest-growing segments of the Internet is the network market. Network systems contain common elements, generally including a dedicated local server to maintain the shared network data, and a communications system for providing data communication services between devices on the network. Data communications services and servers are not easy to configure, manage, and maintain. Thus, there is an incentive for Internet Service Providers (ISPs) to provide such network services and servers, thereby relieving corporations of the burden of providing these services directly.
It is not economically feasible for an ISP to remotely manage servers located on a customer's premises, and support many different customers in this fashion. Rather, an ISP would prefer to offer network services to multiple customers while keeping all of the server host computers within a central location of the ISP for ease of management. Accordingly, ISPs typically dedicate one or more physical host computers as each individual customer's server(s), and maintain each host computer in the centralized facility. This means the ISP will have to own and maintain potentially large numbers of physical host computers, at least one for each customer's server or private network. However, most customers will neither require nor be amenable to paying for the user of an entire host computer. Generally, only a fraction of the processing power, storage, and other resources of a host computer will be required to meet the needs of an individual customer.
Different customers have different virtual server needs. For example, a company A providing large quantities of data and information to its employees and customers will want to ensure that its virtual servers are always available to perform a large number of tasks. Company A may be willing to pay a premium for a guaranteed high quality of service, with high server availability and large amounts of processing power always on-call. By contrast, a small individual B who merely uses his virtual server for back-up file storage space has very different quality of service requirements. Customer B needs (and wishes to pay for) only a limited amount of storage space to be available on an intermittent basis.
When servicing the needs of multiple customers having different needs, it is desirable to provide a virtual server that is dynamic, not static, in its allocation of resources. A customer's virtual server is typically assigned a fixed level of resources, corresponding to either a fixed percentage of the capacity of a particular physical host (for example, the operating system may be instructed to allocate twenty percent of the central processing unit cycles to process A and two percent to process B) or a fixed number of units (for example, the operating system may be instructed to allocate X cycles per second to process A and Y cycles per second to process B). However, customers may be unable to anticipate the exact amount of resources they will require, and a static assignment of a particular resource allocation limit may not allow the virtual server system to adapt to changing customer needs.
Instead of requiring customers to select a static level of resources, a better resource allocation model is structured along the lines of electricity pricing—a customer receives what he needs, and he pays for what he receives. Referring back to a previous example, small customer B may initially request a very low level of resources. However, should his new home business suddenly expand, he may quickly bump up against the limit of the server resources he originally requested. In this case, it would be preferable if customer B's virtual server resources were able to automatically, dynamically adjust to his increased resource needs.
Thus it is desirable to provide a system and method for a virtual server capable of providing quality of service guarantees for a customer, which is also capable of adjusting the quality of service based upon changing customer demand. It is desirable for such a system to dynamically adjust the physical host resources allocated to a virtual server.